How cold can you go?
To test those predictions, researchers recently brought 10 adult male pythons from the Everglades to South Carolina, to see whether they could survive the cooler climate. After implanting a radio transmitter and a temperature logger in each snake, the researchers let them loose in June 2009 in a snake-proof outdoor enclosure.
All 10 pythons did well through the summer and fall, and even survived 12 December nights that were no warmer than 41 degrees Fahrenheit (5 degrees Celsius). Then, in January, the region was plunged into an extremely unusual cold spell. With temperatures dipping below freezing at night for long stretches, the 10 snakes died, according to a paper published in September online in the journal Biological Invasions.
For one thing, the subfreezing temperatures were highly unusual for the region. For another, some studies indicate that the temperatures a snake experiences during its first year determine how it regulates its body temperature for the rest of its life. Snakes born in the area might fare better than snakes transplanted in as adults.
Finally, the pythons that survived the longest were the ones that crawled into underground cavities at night, and Dorcas wonders whether they might have fared even better outside the enclosure.